XACT XTR8 (and other similar) SAT RECEPTION PULSATING

Long story short, I am tryign to get a new XTR8 wroking but the sat level pulses up and down constantly and drops audio too often to be useable.
I already thought it was broken, sent it to XACT directly and got a new replacement, same problem.

Sirius bricked my last XTR8 in November, and I haven't been able to get a replacement XTR8 working.

Has anybody else had this symptom? Sat levels going up and down constantly? I've compared it to other radios side by side, and only the XTR8 is doing this.